From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 27 Dec 2004 14:50:57 -0800 From: "David S. Miller" Subject: Re: Prezeroing V2 [0/3]: Why and When it works Message-Id: <20041227145057.4c5cd651.davem@davemloft.net> In-Reply-To: References: <41C20E3E.3070209@yahoo.com.au> <16843.13418.630413.64809@cargo.ozlabs.ibm.com> <1103879668.4131.15.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: arjan@infradead.org, paulus@samba.org, clameter@sgi.com, akpm@osdl.org, linux-ia64@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Fri, 24 Dec 2004 10:21:24 -0800 (PST) Linus Torvalds wrote: > Absolutely. I would want to see some real benchmarks before we do this. > Not just some microbenchmark of "how many page faults can we take without > _using_ the page at all". Here's my small contribution. I did three "make -j3 vmlinux" timed runs, one running a kernel without the pre-zeroing stuff applied, one with it applied. It did shave a few seconds off the build consistently. Here is the before: real 8m35.248s user 15m54.132s sys 1m1.098s real 8m32.202s user 15m54.329s sys 1m0.229s real 8m31.932s user 15m54.160s sys 1m0.245s and here is the after: real 8m29.375s user 15m43.296s sys 0m59.549s real 8m28.213s user 15m39.819s sys 0m58.790s real 8m26.140s user 15m44.145s sys 0m58.872s -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org